Physiological Mechanisms Associated with Binaural Processing Deficits in Older Adults

Everyday listening activities involve the use of both ears to improve speech understanding, especially in background noise. Basic binaural processing cues lead to a remarkable benefit when trying to understand target speech in the presence of competing speech that is spatially distributed. Several studies have shown that this spatial benefit, based on speech reception thresholds, is similar for older and younger listeners. In contrast, the detection and discrimination of other binaural cues, such as the binaural masking level difference, is poorer in older than younger adults. Such age-related declines have been attributed in part to changes in central auditory function. To better understand the mechanisms that may underlie age-related binaural and spatial processing deficits associated with everyday listening, neural function in the central pathway has been assessed across a range of tasks using evoked and event-related potentials (ERPs) and ongoing neural oscillations. In general, older adults typically have more robust responses than younger adults, consistent with an age-related reduction in central inhibition, and more recent data show a broader distribution of neural activity across hemispheres, consistent with reduced hemispheric asymmetry with age. Implications of these and other findings for clinical evaluation and for developing targeted intervention will be discussed.

Learning Objectives:
After completing this activity, participants will be able to:
1. Understand the impact of age-related auditory deficits on everyday listening.
2. Describe some of the neural mechanisms and physiological markers underlying those deficits.
3. Discuss how physiological measures may be used to index targeted intervention.